"His followers called him Mahasamatman and said he was a god.
         He preferred to drop the Maha- and the -atman, however, and
         called himself Sam.  He never claimed to be a god.  But then,
         he never claimed not to be a god.  Circumstances being what
         they were, neither admission could be of any benefit."

The style of this book is unusual, and a bit difficult: The story is not told in a smooth narrative, but in a series of short, often disjoint, episodes, and by the time the tale is done, most of these episodes have fallen into place. My personal judgment is that Zelazny could not make this work as well as he'd hoped, but that it's a remarkable effort. The book is probably best known, though, not for its Egyptian gods and their struggles but for Madrak, the all-bases-covered agnostic preacher:

        "Then into the hands of Whatever May Be that is greater
         than life or death, I resign myself -- if this act will
         be of any assistance in preserving my life.  If it will
         not, I do not.  If my saying this thing at all be
         presumptuous, and therefore not well received by Whatever
         may or may not care to listen, then I withdraw the statement
         and ask forgiveness, if this thing be desired.  If not,
         I do not.  On the other hand --- "

At the center of reality is the land/kingdom/universe of Amber. Emanating from it are the Shadows -- other universes or realities -- and members of the royal house of Amber have the ability to walk from one Shadow to the next. In an infinity of Shadows, any world that can be imagined exists somewhere. (Or perhaps they only come into being when they are imagined; is there any way to know? In either case, knowledge and imagination seem to impose limits: There is no indication, for instance, of anyone being able to walk to a hypothetical world of super-advanced technology and bring some of that technology home.) In some sense, though, Amber itself is more 'real' than the Shadows, and when Oberon, its ruler, disappears, it is for Amber that his nine sons compete.

Corwin, the hero of this story, is competing at a particular disadvantage: Most of his opponents don't know that he has lost his memory, and is running a very long bluff. In the process of his relearning his way through Shadow universes and shadow politics, the reader is also introduced to this fascinating and ambitious setting. "Nine Princes in Amber" is the first and best of the series. The story goes on too long as, in the succeeding novels, "The Guns of Avalon" (***), "Sign of the Unicorn" (**), "The Hand of Oberon" (**), and "The Courts of Chaos" (**), the story becomes more and more convoluted, and Corwin works out who is betraying what to whom. The second Amber series, which starts with "The Trumps of Doom" and follows Corwin's son, is definitely too long and too convoluted. (I really ought to wrap this up with a clever quote from "Nine Princes in Amber", but none comes to mind. It's not that kind of a book.)

        "So feathers or lead?" I asked him.
        "Pardon?"
        "It is the riddle of the kallikanzaros.  Pick one."
        "Feathers?"
        "You're wrong."
        "If I had said 'lead'...?"
        "Uh-uh.  You only have one chance.  The correct answer is
        whatever the kallikanzaros wants it to be.  You lose."
        "That sounds a bit arbitrary."